The present invention relates to receiving multiple beams for rapid acquisition. In particular, multiple beams are formed in response to each single transmission of acoustic energy with reduced geometric distortion and clutter.
Multiple receive beams are formed in response to a single transmit firing. Forming multiple receive beams for each transmission increases the scan rate. However, the amount of transmitted energy varies as a function of distance from the center of the transmit beam. Receive beams spaced furthest from the center of the transmit beam may be associated with higher levels of geometric distortion and clutter. The two-way spatial response may vary as a function of the location of the receive beams, resulting in shift-variance.
Clutter levels may be reduced. For two dimensional imaging, the position of the receive beams is shifted as a function of distance away from the center of transmit beam. U.S. Pat. No. 5,779,640 deals with multi-beam distortion corrections for two dimensional imaging.
For three dimensional imaging, a plurality of planes or a volume is scanned. To further reduce the scan or increase the frame rate, more receive beams may be formed in response to each transmission. However, the formed two-way beams may introduce undesired clutter and distortion.